Load hook connection



May 10, 1949. c. s. SCHROI'EYDER' 2,469,612

LOAD HOOK CONNECTION Filed Aug. 25, 1944 lmmull INVENTOR C, -o a er ATTORNEY Patented May 10, 1949 Charles S; Schroeder,- Philadclphia, Pa., assignor to. The Yale '80. Towne Manufacturing Company, 1S tam'f0rd,.'. Conn., a corporation of Connecticut flAppliczition' August 25, l9l4gseriall Nor 551,127

( Cl. SQ-86) 2 Claims.

:1 This invention relates to a. chain" hoist or the type disclosedinmy Patents Nos. 2,335,571 and 2,342,091. Inchain hoists of the class described, .the chain utilized is-of the sprocket actuated type in whichv the links are-pivoted :to one-another about a series of para-llel'pivots. v lhereiore; the

chain isrflexi-ble in one plane only.

I have found that chain of the particular type is susceptible. to breakage when associatedrinza conventional mannenwith a clevis and hook block. Thus, it is common the prior; art. to mount the hook block for pivotal movement relatively- 110 the vclevis andzthen mount .the yokes :of the clevis: forcpivotal/movemeut'. :rela- :tivelyto. a clevis support;v with. the .clevis :sup-

portv being itself pivoted to the lastof the chain links on: an. axisparallel to the'parallel pivots 1.1T the chain links. Because the yokes of the clevis arerpivotally mounted-s relativelytotheuicl-evis support about an axis very closeto theaxis onwhich: the clevis support :is pivotedi:to that-last .chain link, but. at rightangles thereto, it' lbecomespossible to move the hook andxhookblock together-with the yokes of the clevis-in-sucht.a

.manner. as to kink thealinks LottzheBchain, placing themin an unnaturalposition. armatterof tact, through this: positioningv of the chain links the effective length of thechain.isalso'sdecreased.

Itnth-en. 'someti1nes -'occurs that when a heavy load is assumed by the chain through the hook and hook block, .the chain-will not bear up under the load because. of itsunnatural position. In addition, because the effective. length of the chain is decreased, it will strike the hoist as it moves upwardly so as to damage the" hoist. This is, of course, made possible because the limitimechanismdoes .not function elf ectively. with the chain in its unnatural position.

It is the object of-my invention to provide means-whereby it will befimpossible to place'the :chain in the unnatural kinkedzposition. that has been found so objectionable by the industry. Ihave found that if the hook 'block is not allowed to pivot sharply with its clevis at right angles relatively to the lowermost chain link, as is possible in present structures where the clevis is pivoted on a clevis support itself pivoted to the chain, no kinking may occur. I, therefore, arrange for the mounting of the hook block for pivotal movement at right angles to the parallel pivots of the chain links as is required for manipulation of the hook, but about means that will prevent the pivotal movement that I have found to be the cause of the difficulties now encountered. As a further feature of my :i-nivention, the mounting-:means for the hook block are preferably pivoted'to'the' chain about a "pivot shaft. parallel to the pivots of the chain links.

As adetai-lieature of'my invention, liutilize substantially the structure of 'the v priorart-witl'i the clevis :and clevis support arranged .toiorm :a functionally unitary member.

= Iahaye thus :set iorth the naturewof my :invention in order that those. skilled in the 'art.may better appreciate :the relation/of the invention to *theaprionart, andthe contributionmadethereby.

While also .I have indicated.thepperative theory :iofzmyinvention, it should be understood that. I may -notr be=entirely correct in that theory and that my invention should not-be limited thereby.

.':It is further emphasized that :inreducing my "invention: to :practice, I have, preferred :using mechanical means now employed in the art so .asttoxreducethe cost of my invention, and that --my: inventionish'ould not be llimited to the "said .means :since othermechanisms for contributing the results-of inventionwill readilyoccur to v th'ose skilled-in theart.

Referring now totthe drawings,

a. 1 is aperspective'view of a chainshois'titoi' :thetypeto \vhichrmy .inventionr'is applied, the aparticuiar hoist being. well illustrated rand .de- :scribed .my .paten'ts supra.

Fig. 2 'is an. enlarged. view: of thermeans. utilzized for securingithe hookblock tothe .chainof theihoist wilth :Jcertain parts shown :in section.

Fig; 331 villustrates just? how the chain of 1 :the -'prior artmay be kin ked lay-the means now: utilized .iror securing the: hook block to the chain.

Fig. 4: is a section i taken along alines 4- 4 0f; .Fig; 2.

:JReferring' now more particularly to the draw- :ingstthe chain'hoist in: Which my invention is incorporated-is indicated generally by reference .numeral I10 andrutilizes ansprocket actuated rlo'ller load chain indicated generally by reference numeral l I. This roller chain comprises a series of links 12 pivoted to one another about parallel shafts l3 so as to be flexible in but one plane. It is, of course, understood that operation of a sprocket within the hoist It] will move the chain ll upwardly and downwardly.

In the prior art the lowermost link I2 of the chain II has pivoted thereto about a shaft I4, a clevis support I5. This clevis support 15 supports a clevis indicated generally by reference numeral l6, and having a pair of yokes ll. These yokes I! are pivoted to the clevis support l5 about a horizontal axis substantially along the 3 line l3 illustrated in Figs. 1 and 3. The yokes I! support at their lower ends a hook block IS, the hook block l9 rotating relatively to the yokes H on a horizontal axis parallel to the line I 8. The hook block l9, of course, supports a hook 20 that is to be attached to the load.

It is possible for the relatively heavy hook 20 and hook block l9 to move the yokes ll about the axis of the line l8, after which the movement of the clevis support I about shaft M will carry the clevis It downwardly so that the chain II will assume the kinked and unnatural position of Fig. 3. If a load is now applied to the hook 2E3, the chain because of its unnatural position, may be deformed or broken either upon assuming the load or after moving to an upper position as has already been indicated generally. Those skilled in the art will fully appreciate this condition and the incidental hazards resulting therefrom.

In Fig. 2 the hook block i9 is shown mounted on the yokes I! about horizontal arms 2| extending from the hook block, so that the hook block may pivot relatively to the clevis as in all prior art structures, and as set forth supra. The yokes I! are secured to the clevis support l5 so as to be incapable of movement relatively to the said clevis support. For the particular purpose, as best illustrated in Fig. 4, the extending arms 22 of the clevis support are formed square and they fit in square openings 23 in the upper ends of the yokes ll. It is, of course, possible to arrange in other ways for the securing of the yokes to the clevis support IS in a manner which will not allow pivotal movement between the two. Thus, the ends of the yokes and the ends of the arms of the clevis support 15 of the structure of Fig. 3 may be deformed to yield the same results. As a further possibility, the clevis support 15 and clevis it may be formed as a unitary casting. In the claims of this application they are so considered and are termed a hook block support.

It will now be readily appreciated that the hook block l9 will still be rotatable as in Fig. 3 on a horizontal axis relatively to the clevis l6 and the yokes I! thereof. However, a sharp pivotal movement of the clevis l6 relatively to the clevis support It is now not possible. It is now only possible to pivot the clevis [6 about shaft 14 relatively to the chain ll. Since clevis I6 is quite a bit longer than any chain link, the weight of the hook block I9 is always so disposed as to exert considerable force tending to maintain the hook block in the position of Fig. 2 and thereby to prevent the unnatural kinking of the chain. This is further true because hook block I9 is pivoted to the hook block support comprising parts I 5, it on an axis at right angles to the axis on which the said hook block support is pivoted relatively to the links of the chain. Therefore, it becomes impossible to move the hook block and chain into an unnatural position of the class indicated in Fig. 3.

A chain and hook block connection such as is illustrated in Figs. 2 and 4 has been tested repeatedly under all conditions and it has been absolutely impossible to manipulate the parts into a position of the type which has been found troublesome and dangerous. Those skilled in the art will now readily perceive that by a simple change of present structures, well known c0mmercially, I have been able to obtain an extremely desirable and long sought result, and a result that has not been secured by others with mechanisms much more complicated and costly than that which I have herein shown and described.

I believe that the operation and construction of my invention will now be apparent to those skilled in the art.

I now claim:

1. In a combination of the class described, a sprocket roller load chain of the type having links that are pivoted to one another about parallel pivots so that said chain is substantially flexible in one plane only, a hook block, a clevis having a base and a pair of arms rigidly fixed thereto, said base being pivoted to the last of said links on a pivot axis parallel to said parallel pivots whereby said clevis is flexible relatively to said chain in only said one plane, and means pivotally mounting said hook'block on the arms of said clevis on an axis at right angles to said parallel pivots.

2. In a combination of the class described, a sprocket roller load chain of the type having links that are pivoted to one another about parallel pivots so that said chain is substantially flexible in one plane only, a hook block, a clevis having a base and a pair of arms rigidly fixed thereto, said base being pivoted to the last of said links on a pivot axis parallel to said parallel pivots whereby said clevis is flexible relatively to said chain in only said one plane, and means pivotally mounting said hook block on the arms of said clevis on an axis at right angles to said parallel pivots, the distance on said clevis between its pivot to said chain and the pivot axis of said hook block, being at least as great as the length of two of said chain links.

CHARLES S. SCHROEDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,561,787 Jones Nov. 17, 1925 FGREIGN PATENTS Number Country Date 9,275 Great Britain Apr. 24, 1903 

